1. Field of the Invention
This invention relates to a system and accompanying method for economizing the operation of a vehicle's engine by activating the transmission thereof and automatically shifting the transmission from a low drive gear to a neutral gear when driving engagement of the gears is not necessary, but operation of the engine is still maintained, thereby reducing wear on the engine and gears, conserving fuel and energy, reducing the amount of pollution generated by the vehicle's engine which is exhausted into the atmosphere and reducing wear on the braking system as it does not have to overcome an engines driving force to keep the vehicle in a stopped orientation.
2. Description of the Related Art
In modern day travel, motorized vehicles such as automobiles, trucks, etc. typically incorporate the use of an automatic transmission to regulate engine operation. Specifically, automatic transmissions of the type referred to are activated or controlled by mechanical, electronic and/or computerized control systems which sense the various conditions of the vehicle, including but not limited to vehicle speed, for transferring the gear train automatically between a plurality of drive gears. The number of drive gears in modern day automatic transmissions of course may vary typically from two drive gears to four drive gears.
In addition to the drive gears, automatic transmissions also include a reverse gear and a neutral gear. However, the reverse and neutral gears are configured such that they can only be obtained by manual activation of the transmission by the driver or operator of the vehicle. As can be appreciated, the positioning of an automatic transmission into the reverse gear is restricted to manual control for safety reasons. Specifically, under no practical circumstances would an automatic transmission be designed for automatic shifting into a reverse gear during the operation of the motorized vehicle in a forward direction. Such an inadvertent shifting and direction change into reverse at the wrong time could cause severe damage to or destruction of the transmission, as well as threaten the safety of the passengers of the vehicle.
There are apparently similar beliefs concerning the automatic shifting of a transmission into the neutral gear. However, as will be pointed out in greater detail hereinafter, such beliefs are now considered to be completely false. While the automatic down shifting of a vehicle transmission through the lower drive gears and into the neutral gear is virtually unheard of, prior art attempts have been made to regulate the automatic down shifting of the gear train of a vehicle transmission. Previously known control systems, while possibly varying in design and operative features, are normally directed to taking advantages of the well known "braking effect" of the engine occurring when the transmission of a vehicle is down shifted and the speed of the vehicle is greater than the conventional speed at which the automatic transmission would normally accomplish a down shifting. The vehicle engine's "braking effect" is commonly used by an operator of an automobile having a multi-speed, manual transmission to slow the vehicle without applying the brakes thereof. Therefore, while conventional control systems may be designed to interact with known vehicle automatic transmission systems and may incorporate a variety of different features and/or operative characteristics, none of the known transmission control systems include the automatic down shifting through one or more drive gears and into a neutral gear in an automatic fashion based on specific operating conditions of the vehicle.
Indeed, it would be extremely beneficial to devise and incorporate a control system designed to automatically down shift a vehicle transmission into the neutral gear. For example, even though vast improvements have been made in the reduction of pollution generated by the operation of motor vehicles incorporating gasoline powered internal combustion engines, pollution still remains a major problem and a serious threat to the world's environment. There are, however, still numerous and prolonged periods during the operation of a motor vehicle wherein the vehicle travels at a relatively low speed resulting in the vehicle's engine operating at significantly low R.P.M. Under such operating conditions, it is also common for the operator of the vehicle to continuously and/or repeatedly activate the braking system of the vehicle by engaging the foot operated brake pedal in the conventional fashion. During such periods, the automatic transmission of the vehicle is maintained in the lower ranges of the gear train of the automatic transmission. During such "low demand" operating conditions of the vehicle, it would be beneficial to provide a system which can automatically shift the transmission into the neutral gear as that would greatly reduce the load placed on the engine of the vehicle, and proportionally reduce the fuel consumed and the pollution generated. Operating conditions of the vehicles of the type set forth above typically occur when the operator is traveling in extremely heavy "bumper to bumper" traffic or when the vehicle is designed or intended for use as "pick-up and delivery" vehicle, wherein numerous stops and/or unusually slow travel of the vehicle is required.
Therefore, there is a need in the industry and in the design and manufacture of motorized vehicles, particularly automobiles, buses and trucks, for an improved control system and associated method for economizing the vehicle's engine operation and minimizing wear on the transmission. Such an improved system and method should be structured so as to operate only when the vehicle is to be stopped so as to avoid possible safety hazards associated with required acceleration, and should operate only under particular conditions, such as when engine operation economization can be safely and effectively taken advantage of. Moreover, an improved system should also preferably be adaptable for use with existing vehicle engine designs without detracting from the normal operation thereof or requiring significant modifications.